Because recent studies indicate a dramatic increase in the rate of drug abuse, law enforcement officials must develop a program that successfully addresses the problems created by the drug-impaired driver. Successful apprehension and prosecution of such offenders depends upon basic knowledge of pharmacology, of how drugs effect the human body, of how drugs are used by abusers, of appropriate evidence-gathering techniques, and of effective trial strategies. All drugs causing impairment can be categorized as depressants, psychedelics, or stimulants. The law enforcement officer should be familiar with both the proper names and slang terms used to identify these drugs. In addition, it is essential to know that many drugs interact with each other and with alcohol to produce driver impairment. questioning guestioning at the scene of an accident during the officer's initial investigation has been excluded from the requirement of Miranda warnings. Admissions that are made voluntarily are admissible in court. Vehicle searches are justified under a number of search and seizure rules. Medical examination of the defendant at a hospital, including blood and urine tests, can provide valuable evidence regarding drug use. The prosecution generally has the advantage on cases involving drug abusers who drive under the influence. Many State statutes provide that any person who is a habitual user of narcotic drugs not operate a motor vehicle. Two appendixes and 98 footnotes are provided.